Similan Islands in August
Not the best time
Worst month weather-wise with islands completely inaccessible. Even mainland areas struggle with flooding and transportation disruptions during heavy storm periods.
Weather
Monsoon peaks with daily torrential downpours and violent storms. Seas are consistently rough with poor visibility. Humidity reaches oppressive levels throughout the day.
30°C high24°C low22 rain days
Crowds & Cost
low crowds
~$70/day average
Events & Festivals
- •Queen Mother's Birthday
- •Mother's Day in Thailand
August Tips
- •Islands closed - no exceptions
- •Mainland Thailand experiences flooding in low areas
- •Book accommodations with covered walkways
All Months
The islands close completely from May 15 to October 15 due to monsoon conditions. Your window runs November through April, with distinct seasons within that period. November and December offer the calmest seas and best visibility for diving - often 35-40 meters. But expect higher prices and crowds, especially around Christmas. January through March delivers the most reliable weather with minimal rain and gentle breezes. This is peak season, so book accommodations and liveaboards well ahead. April sees rising temperatures (35°C daily) and occasional afternoon storms, but fewer crowds and better deals. The shoulder months of late October and early May can be spectacular if weather cooperates, but you're gambling on conditions. Water temperature stays warm year-round at 27-29°C. Northeast monsoon winds from December to February can make some dive sites choppy, but generally create better visibility.
Similan Islands Scores
Solo
7/10
Couples
8/10
Families
6/10
Adventure
9/10
Budget
5/10
Luxury
7/10
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